Part 3
WM 1001Z2 Assembling V8 4.8-litre DFI engine as of October 2008
18. Fit crankshaft holding bridge holding bridge 9677/1 in the centre of the crankshaft.
Crankshaft secured
19. Turn upper part of crankcase and oil cylinder liners.
20. Tension piston using a commercially available piston ring restraining strap (e.g. Universal piston ring restraining strap Nr.55 ) or assembly funnel funnel 9784/1 and press piston into cylinder. When doing so, make sure that the direction of travel arrow on the piston crown is pointing in the direction of travel and the connecting rod code has been fitted facing the exhaust side. Push the pistons in until the connecting rod bearing is lying on the con-rod journal of the crankshaft. Once all the pistons with connecting rod have been pushed in, fit connecting rod cap evenly and synchronously with the correct bearing shell. Fit with new connecting rod bolt to the prescribed tightening torque. For details, see -> 131020 Removing and installing pistons on 4.8-litre DFI engines 131020 Removing and installing pistons on 4.8-litre DFI engines
Piston, connecting rod
Tensioning pistons
Piston assembly
Pressing in pistons
21. Remove crankshaft holding bridge. Apply Doboseal 224N sealant (999.915.573.43, status 09/08) to the lower part of the crankcase. Insert sealing ring -3- into the upper part of the crankcase and position the lower part of the crankcase onto the upper part of the crankcase. Insert all the fastening screws, fit to the prescribed tightening torque within 5 minutes and wipe off excess sealant.
Applying sealant
22. Tighten M11 and M10 bearing screws to the prescribed torques. -5 and 6-
Tightening sequence for thrust-bearing screws
Lower part of crankcase
23. Fit cross bolt connection.
Tightening sequence for securing lower part of crankcase to upper part of crankcase (cross bolt connection)
24. Fit M8 screws on the side -8 and 9-. Remove emerging sealant.
25. Punch in or imprint the engine number if necessary (when replacing engine).
26. Move oil plate with all the seals into installation position and secure to the lower part of the crankcase. => Tightening torque: 10 Nm (7.5 ftlb.)
Oil guide (oil plate)
27. Grease sealing ring between the oil plate transfer pipe and oil pump sparingly with Kluber Syntheso GLEP 1 and fit oil pump. Secure the oil pump.
Oil pump on turbo engine M48/51 with oil extraction stage
28. Fit oil pump sprocket with drive chain with respect to the crankshaft chain pinion => Oil pump chain. Counter the oil pump sprocket at the oil pump using a screwdriver and fit a new screw. 1st turn => Initial tightening: 20 Nm (15 ftlb.) ; final tightening (torque angle) => Torque angle: 90°
Oil pump chain
Countering oil pump pinion
29. Fit cover plate for oil pump drive using three screws. => Tightening torque: 10 Nm (7.5 ftlb.)
30. Turn engine and clean sealing faces. Blow out bores of cylinder head screws. Position both cylinder head seals. Part number/marking facing upward. When doing so, make sure that the cylinder head gasket is positioned on the dowel sleeves.
31. Unscrew front camshaft mounting saddles (lower parts) of the cylinder heads (if you have not already done so), as the bores in the cylinder head screws are covered. see illustration, item 8
Camshafts, cylinder bank 1 to 4
32. Position cylinder heads, insert cylinder head screws and fit them. Observe tightening sequence and prescribed tightening torque.
Cylinder head 1 to 4
Tightening sequence for cylinder head
33. Fit front M8 screw of cylinder head 1 to 4. => Tightening torque: 23 Nm (17 ftlb.)
34. Make sure that the intake openings have been protected using adhesive tape or something similar to prevent them from becoming dirty.
35. Insert front camshaft mounting saddles (lower parts) of cylinder heads. Item 8
Camshafts, cylinder bank 1 to 4
36. Coat camshaft bearings with normal multipurpose grease or engine oil.
37. Insert bucket tappets into the cylinder head if necessary (bucket tappets for intake and outlet side have different diameters). The bucket tappets have a twist lock that fits into a guide groove in the cylinder head. Fit used bucket tappets at the same position.
38. Position vibration balancer with screw tightened by hand. Turn crankshaft to just before cylinder 1 TDC (prevents the valves from sitting on the piston when directly at TDC). Item 2
Staking bore 45 ° before TDC
Information
A data matrix coding is shown on the staking dihedron of the camshafts. This is a square black/white dotted marking used for electronic identification purposes during the production process. This marking can be used as an aid when inserting the camshafts into the cylinder head. All four camshafts press against the valves the least when the data matrix coding is facing upwards during installation.
39. Insert camshafts so that the minimum amount of pressure is exerted on the valve springs and coat bearing locations with normal multipurpose grease or engine oil. Position housings correctly and screw down. The housings are numbered and marked with E (intake) or A (outlet). Fit camshaft housings evenly and gradually, and slowly tighten to the specified tightening torque. The camshafts must not be strained or tilted. Outlet camshafts and intake camshafts (also bank-specific) cannot be used interchangeably because of the bearing locations and length.
Camshaft identification on V8 turbo engine M48/51
Camshaft housing identification
Camshaft mount, cylinders 5 to 8
40. Move both hydraulic valves for camshaft control into installation position and fit them. Item 5
Camshaft control
41. Insert oil vent line at the firewall side of cylinder 5 and screw it on. Grease sealing ring sparingly with Kluber Syntheso GLEP 1.
Vent line
42. Fit threaded peg for tensioning and guide rails. Items 1 and 2
Timing chain and chain guide
43. Fit guide rail with oil pump chain tensioning rail and pull locking pin (tensioning rail will be released).
44. Fit "U"-shaped deflection rail item 4.
Timing chain and sprockets
